The present disclosure relates to drill bits and more particularly to custom shaped blanks for use in manufacturing drill bits.
In traditional molding of drill bits, molten metal flows into a hollow mold assembly containing a blank. Blank designs are typically axial-symmetrical, with constant outer diameters, inner diameters, tang outer diameters, and tang lengths for a given design. In order to avoid nozzle displacements and maximize steel volume in the mold assembly, the tang outer diameter, length, inner diameter, angle, and thickness of the blank may be varied while maintaining axial symmetry. Junk slots may be formed in the drill bits by providing sand or other material in the mold assembly at the desired location of the junk slot. However, the junction between the junk slot sand tip and the blank results in webbing in the resulting matrix bit. This webbing is a triangular-like piece of material left in the junk slot between blades of the drill bit after other excess material has been turned off of the drill bit. Such webbing is typically ground away, which is time consuming and costly, may be damaging to the matrix bit, and may pose a safety risk.